Reflector for incandescent lamps



y 6,1930. I P. HENNINGSEN 1,757,527

REFLECTOR FOR INCANDESCENT LAMPS Filed Nov. 13. 1926 Patented May'6,1930 UNITED STATES PATENT ornca POUL HENNINGSEN, OF CHARLOTTENLUND, NEARCOPENHAGEN, DENMARK, A SSIGNOR TO MESSRS. LQUISJEOUI SEN & COMPANY, OFCOPENHAGEN, DENMARK REFLECTOR FOR mcnnnnsonnr LAMPS Application filedNovember 13; 1926, Serial No. 148,164, and in Denmark December 4, 1925.

The present invention refers to a reflector arrangementvfor emittingdiffused light and in particular to a special arrangement in suchreflectors which consist of a system of' lamp shades which completelysurround the source of light 'so'that no radiating-rays can meet the eyedirectly.

The characteristic feature of the invention consists inthe fact' thatshade surfaces are turned towards the source of light at an angle theindirect and semi-direct light) will be 60 of less than 45 degrees withthe rays of light. But the shape of the shades only forms in figurativemanner. a part of the present in-, vention and in their distributionregard has only been taken to produce a suitable air cool- With thecustomary dullness of the spherical glass bulb of incandescent lamps orby surrounding the lamp with a clouded globe the filament will becompletely surrounded by a white surface so that, if the eye be assumedto be in the place of the filament, it would only see a White or otherdiffuse surface in all directions a By the present invention the sameobject is attained, as the eye, assumed to be in the place of thefilament, will only be able to see difl'use surfaces, but the featurewhich is decisive for the lighteconomy and which forms the basis for thepresent invention consists in the fact that all these surfaces, contraryto the inner surface of the clouded spherical surface around thefilament, will form an angle of less than with'the rays of light. It isthereby obtained that the light which is necessarily reflected by thediffuse surfaces owards the filament (and heats the same, and

the gas of the lamp), become essentially less than if the angle of thesurface with the rays of light proceeding from the filament is more than45 degrees. I l

In order to increase the utilization of the light the diffused lightwhich is reflected from a diffuse surface to the back of the diffuses'ur face below it, must be utilized as greatly as possible andtherefore the back of the shades are made bright or as mirrors,

The light arrangement which closest approaches that here described isthe simple incovered with dust. Besides all surfaces are here placed atan acute angle to the rays of light. v

The invention has, in a single modification, been shown in the drawing,in which Fig. 1 is a vertical section through such a system of shades, aFig. 2 is a sectional view showing the reilection from a small part of adiffuse reflecor. i

It should be here said that the drawing should only be considered as adiagram for explaining the invention, and all parts which are notnecessary for understanding the in- VBIltlOIl-llfiVB therefore beenomitted- In the drawing the numeral 1 indicates the filament of the lamp2 and above the same is disposed a shade 3 the curvature of which issuch that the light will never strike the shade at an angle of less than45 degrees with the perpendicular. Beneath this shade but with its upperedge on a level with the lower edge of the shade 3 is disposed anothershade 4 with the same curvature and position relatively to the rays oflight.

Lastly a third shade 5 is disposed beneath this shade 4 with the samecurvature and so arranged that no dire'ctrays of light can pass betweenthe shades 3, 4 and 5. Lastly an undershade 6 is provided which may bebright on its inner side and which reflects the light onto the dulledshades. This form a part of the invention.

In the drawing it is shown that the rays of light 9, 7 and 11 emitted bythe filament onto the shades 3, 4 and 5 will be spread as shown byarrowsso that the strongest light effect will be in the directions 8, 10 and12.

"In Fig. 2 this circumstance is more closely shade does not i explained.13 is the surface of one of the dullshades 3,4 or 5. l The light from,the filament is indicated the line and strikes 7 against the shadewithin the'shaded angle 24 the bordering lines of which are 13 and 14.The ray mentioned 15 when reflected by the surface 13 will assume theform of a bundle of rays, hereindicated by the numerals 17 18, 19, 20,21, 22, 23. The size of these rays will differand the ray 17 will alwaysbe greatest, but the difierence in their size will dependon the dullnessof the shade;

It is thus possible to regulate the light emission from a lamp byvarying the degreeof dullness of the shades or of parts or individualportions of them whereby the rays 8,. 10 and 12' in Fig. 1 will beincreased relatively to the other emission.

It is hereby rendered possible, in an easy manner, to let the light fromthe shade become essentially luminous towards outside, that is to say tospread the light more in a room with great dullness of the shades,whereby the rays '8, 10 and 12 willbe weakened, or to gather the lightgreatly towards the centre with slightly dull shades, chiefly the outerpart of shade 3, the whole shade 4 and the upper part of the shade 5Q Itis-evident that the incident ray 15 forms an angle with theperpendicular which is greater than degrees (the angle between 14 and16).-

The intensity of ray 1? will be determined bothby the dullness of shade13 and by the angle between 15 and 16 being as large as pos-' sible. Itis therefore essential that the ray I 15 falls within the shaded area 24between the lines 13 and 14, as it then willJalways form I eperpendicular which is an angle with th greater than 45.

Having now described my invention, what I claiin as new and desire tosecure by Letters 4 light, the inner surfaces ofsaid shades being Patentis A reflector for diflusing the light of incandescent lamps comprisinga plurality of concentric downwardly concave shades disposed above andbelow the plane of the source of directed toward the source of light,the surfacesof said shades making at all points angles of lessithan 45with a line to the source.

of light, the inner surfaces of the' shades being dulled. i

' In testimony whereof I-aflix in signature. POUL HENN NGSEN,

